Bert -
Are you discussing cleaning the wheel barrel. IMO, get both. The WW has been a barrel cleaner in mainly the Medium and the Small (to get in the minutia of caliper/wheel). The head is round, and the shaft is thin enough that it allows you to get inside the angle and angle/scrub as one should ....
The Blade is nice but IMO it's a single function tool. It is flat and allows you to get inside a spoke and reach all the way in *can scrub a 11 1/2" wheel with ease*.
Where is fails is the profile is flat and *wide*. It doesn't work well for me to scrub/move the wand much aft' left or right due to this shape, and this is in a *wheel spoke* opening that I could move freely everyday and anyway with my Wheel Woolie.
Personally, one will always need a mitt of any sorts for the spokes It' allows you to hit the faces, behind the spokes, etc - super quick with a mitt.
I used to clean wheels with the *swissvax* brush primarily. And it's still a great tool for getting into profiles/pockets of the wheels pokes, etc.
But a mitt is the main *front wheel face/spoke* tool of choice